École Polytechnique Fédérale de Lausanne
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Le Moyen-Orient aux XIXe et XXe siècles : au croisement de la continuité technologique et de l’intrusion de la modernité occidentale
No full textLHS
Neuromodulation/neurostimulation system for restoring a motor function and facilitating neurological recovery
No full textThe present invention relates to a neuromodulation/neurostimulation system (100) for restoring a motor function of the upper and/or lower limbs and facilitating neurological recovery in a patient (P) with spinal cord injury (SCI) and/or other neurological disorders, said system (100) comprising: a processing unit (10), which is configured and adapted provide stimulation commands; an implantable or external stimulation unit (12), which is configured and adapted to deliver neuromodulation therapy, in particular epidural electrical stimulation (EES) to the dorsal roots of the spinal cord (SC) of said patient (P); at least one implantable or external pulse generator (14), operatively connected to the stimulation unit (12); an implantable neurosensor (16) including electronic components that are configured and adapted to detect electrocorticographic (ECoG) signals from the sensorimotor cortex (C) of said patient (P), denoting a motor intention of said patient (P), wherein the processing unit (10), the stimulation unit (12) and the implantable neurosensor (16) are operatively connected to define a brain-spinal interface (BSI), and wherein the processing unit (10) is configured and adapted to: collect and decode, preferably in real-time, the ECoG signals from the sensorimotor cortex (C) into a corresponding motor intention of said patient (P); converting, preferably in real-time, the decoded motor intentions into corresponding stimulation commands, and forwarding, preferably in real-time, the stimulation command to the at least one pulse generator (14).AVP-R-TTOAlternative title(s) :
(fr) Système de neuromodulation/neurostimulation pour restaurer une fonction motrice et faciliter la récupération neurologiqu
High-brightness transition metal-sensitized lanthanide near-infrared luminescent nanoparticles
No full textThe demand for near-infrared (700–1,700 nm) materials in optical communications, laser sources and biological imaging applications has led to extensive research on lanthanide-doped nanoparticles, owing to their nanostructure modulation and interface property tunability. However, the low molar extinction coefficient of conventional lanthanide sensitizers limits the brightness of lanthanide near-infrared nanoparticles for applications in low-power excitation scenarios. Here we introduce Na3CrF6, a new crystalline nanoparticle that serves as both sensitizer and host for high-brightness near-infrared emission from lanthanide activators (Er3+, Tm3+, Yb3+ or Nd3+). We demonstrate an increase in brightness of up to 370 times compared with the most intense conventional lanthanide-sensitized nanoparticles. This discovery is also validated for other lanthanide-doped nanoparticles sensitized with low-cost transition metals (Mn2+ or Ni2+). Our transition metal-based nanoparticles represent a powerful toolbox to enable high signal-to-noise-ratio labelling and imaging with low-power excitation sources such as white light-emitting diode or persistent luminescence materials. This work paves the way for next-generation high-brightness near-infrared luminescence systems, suited for a wide range of low-illumination excitation applications.PH-S
Hardware-in-the-loop training for lensless imaging with a programmable mask
No full textLensless imaging can drastically relax traditional camera constraints by replacing lenses with optical masks, enabling lighter, cheaper, and thinner systems. However, unlike lenses, there is a lack of clear criteria for optical mask design. Most approaches are heuristic: either selecting a random mask or designing one with desired spectral and/or directional filter properties. Recent work jointly optimizes a phase mask and a task-specific neural network, but in simulation. We propose and demonstrate hardware-in-the-loop (HITL) training for jointly optimizing the mask and reconstruction parameters of a lensless imaging system, using the physical system itself in forward passes and a simulated model for determining updates during backpropagation. As the physical system uses a programmable mask, system updates can be done during training. Results show significant improvements in image quality metrics (2.14 dB in PSNR, 21.4% relative improvement in a perceptual metric) by jointly learning mask and reconstruction parameters. A low-cost prototype (less than 100 USD) is used, with open-source training and measurement code available on GitHub: https://github.com/LCAV/LenslessPiCamLCA
Amplitude analysis of the radiative decay Bs0→ K<sup>+</sup>K<sup>−</sup>γ
No full textA search for radiative decay of Bs0 mesons to orbitally excited K+K− states is performed using proton proton collisions recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1. The dikaon spectrum in the mass range mKK < 2400 MeV/c2 is dominated by the ϕ(1020) resonance that accounts for almost 70% of the decay rate. Considering the possible contributions of f2(1270), f2′(1525) and f2(2010) meson states, the overall tensor contribution to the amplitude is measured to be (Formula presented.) mostly dominated by the f2′(1525) state. Several statistically equivalent solutions are obtained for the detailed resonant structure depending on whether the smaller amplitudes interfere destructively or constructively with the dominant amplitude. The preferred solution that corresponds to the lowest values of the fit fractions along with constructive interference leads to the relative branching ratio measurement (Formula presented.) where the last uncertainty is due to the ratio of measured branching fractions to the K+K− final state. This result represents the first observation of the radiative Bs0→f2′1525γ decay, which is the second radiative transition observed in the Bs0 sector.LPHE-OSPH-SBLPHE-RMLPHE-L
Observation of the B<inf>c</inf><sup>+</sup>→J/ψπ<sup>+</sup>π<sup>0</sup> decay
No full textThe first observation of the Bc+→J/ψπ+π0 decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1, collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV. The ratio of its branching fraction relative to the Bc+→J/ψπ+ channel is measured to be (Formula presented.) where the first uncertainty is statistical, the second systematic and the third related to imprecise knowledge of the branching fractions for B+ → J/ψK*+ and Bc +→J/ψπ+ decays, which are used to determine the π0 detection efficiency. The π+π0 mass spectrum is found to be consistent with the dominance of an intermediate ρ+ contribution in accordance with a model based on QCD factorisation.LPHE-OSPH-SBLPHE-RMLPHE-L
How are fast tracks organized in adult and pediatric emergency departments in Switzerland? A cross-sectional survey
No full textBackgroundIn response to the challenges faced by emergency departments (ED), including overcrowding and high patient volumes, Fast Track (FT) systems are designed to optimize patient flow, yet their implementation and impact in Switzerland remain understudied. Our study provides a comprehensive description of Fast Track (FT) processes across both pediatric and adult settings in Switzerland and compares challenges.MethodsWe conducted a cross-sectional online survey of ED leadership in Switzerland from May to September 2023, using the WHO SARA framework to explore FT processes. The survey included 28 pediatric EDs and their corresponding adult EDs, with questions addressing FT availability, staffing, infrastructure, and operational challenges. Results were analyzed descriptively, providing insights into FT organization and highlighting barriers to implementation and expansion.ResultsThe survey achieved a response rate of 93% (52/56 EDs). Overall, 68% of surveyed hospitals have implemented a FT system, with a higher prevalence in adult EDs (88%) than in pediatric EDs (59%). The absence of FTs in certain pediatric departments was primarily due to structural and personnel constraints. Most FTs are managed internally by hospitals, employing emergency team members, and occasionally general practitioners, reflecting a tailored approach to staffing based on departmental needs.Despite the strategic organization of FTs, operational challenges persist; 45% of respondents identified staff shortages as a major challenge, particularly in pediatric FTs (63%) compared to adult FTs (32%). Financial barriers, including disparities in external physician compensation, remain significant obstacles to FT expansion.Satisfaction levels among EDs with their FT systems were generally high, with improvements in personnel resource allocation and patient flow frequently reported.ResultsThe survey achieved a response rate of 93% (52/56 EDs). Overall, 68% of surveyed hospitals have implemented a FT system, with a higher prevalence in adult EDs (88%) than in pediatric EDs (59%). The absence of FTs in certain pediatric departments was primarily due to structural and personnel constraints. Most FTs are managed internally by hospitals, employing emergency team members, and occasionally general practitioners, reflecting a tailored approach to staffing based on departmental needs.Despite the strategic organization of FTs, operational challenges persist; 45% of respondents identified staff shortages as a major challenge, particularly in pediatric FTs (63%) compared to adult FTs (32%). Financial barriers, including disparities in external physician compensation, remain significant obstacles to FT expansion.Satisfaction levels among EDs with their FT systems were generally high, with improvements in personnel resource allocation and patient flow frequently reported.ResultsThe survey achieved a response rate of 93% (52/56 EDs). Overall, 68% of surveyed hospitals have implemented a FT system, with a higher prevalence in adult EDs (88%) than in pediatric EDs (59%). The absence of FTs in certain pediatric departments was primarily due to structural and personnel constraints. Most FTs are managed internally by hospitals, employing emergency team members, and occasionally general practitioners, reflecting a tailored approach to staffing based on departmental needs.Despite the strategic organization of FTs, operational challenges persist; 45% of respondents identified staff shortages as a major challenge, particularly in pediatric FTs (63%) compared to adult FTs (32%). Financial barriers, including disparities in external physician compensation, remain significant obstacles to FT expansion.Satisfaction levels among EDs with their FT systems were generally high, with improvements in personnel resource allocation and patient flow frequently reported.ConclusionWhile FT systems in Swiss EDs have enhanced patient care and operational efficiency, their expansion and effectiveness are hampered by staffing and financial limitations. Addressing these barriers requires a collaborative effort to reform health system policies and financial frameworks, ensuring the sustainable implementation of FTs to meet the growing demands of emergency care.LIGH
The Chemical Nature of the Oxide Directs the Stability and Reactivity of Copper|Oxide Interfaces in the Electrochemical CO2 Reduction Reaction
No full textUnderstanding the impact of composition and interfaces between metals and oxides is a goal of interest for many chemical reactions. Herein, we propose a framework to map correlations between the electrochemical behavior of the oxide and the stability and reactivity of metal|oxide interfaces, exemplified by Cu|oxide for the electrochemical CO2 reduction reaction (CO2RR). Copper materials interfaced with metal oxides have emerged as promising CO2RR catalysts for selectivity toward multicarbon products, including alcohols; stability under operation has been reported for some of them. However, design rules are currently lacking. Herein, we propose the synthesis of well-defined Cu-MOx core–shell nanoparticles to investigate and compare the behavior of Cu-ZrOx, Cu-MgOx, and Cu-TiOx. By tracking the speciation and morphological evolution of these model catalyst materials, we find that the cathodic stability of the formed interfaces is determined by the operating potential and phase stability of the pure oxides and by their chemical interaction with copper. We learn that the interplay between these factors shapes the restructuring pathways for Cu-MOx catalysts and eventually drives their selectivity in the CO2RR. The developed understanding can be applied beyond this reaction, and the developed nanomaterials can be used beyond catalysis.LNC
Mimicking women’s endocrine milieu in mice for women’s health-related studies
No full textTo improve preclinical studies and their translation, patient-derived xenografts (PDXs) are increasingly used. They have human-specific tumor characteristics and reflect intra and inter-tumor heterogeneity. However, the endocrine milieu differs between humans and host mice. In light of sex-specific cancer biology and a rise in endocrine-related cancers there is an urgent need to correctly reflect the hormonal milieu in PDX models. We show that female mice of NOD.Cg-Prkdc scid Il2rg tm1Wjl /SzJ (NSG) strain widely used for PDXs has 17-β-estradiol (E2) and testosterone (T) levels comparable to C57Bl6 females but higher progesterone (P4) levels. E2 levels are comparable, T levels are lower and P4 levels higher than those observed in postmenopausal women. Ovariectomy increases T to levels observed in postmenopausal women. Subcutaneous E2 and combined E2/P4 silicon pellets provide NSG females with premenopausal ovarian hormone levels. These procedures humanize the endocrine environment of experimental animals, improving PDX relevance in women’s health-related research.UPBR